module AuthenticatedSystem
  protected
    # Returns true or false if the user is logged in.
    # Preloads @current_user with the user model if they're logged in.
    def logged_in?
      !current_user.nil?
    end
    
    # Accesses the current user from the session.
    def current_user
      @current_user ||= (session[:user_id] && User.find(session[:user_id]))
    end
    
    # Store the given user in the session.
    def current_user=(user)
      session[:user_id] = (user.nil? || user.is_a?(Symbol)) ? nil : user.id
    end
    
    # Check if the user is authorized.
    #
    # Override this method in your controllers if you want to restrict access
    # to only a few actions or if you want to check if the user
    # has the correct rights.
    #
    # Example:
    #
    #  # only allow nonbobs
    #  def authorize?
    #    current_user.login != "bob"
    #  end
    def authorized?
      true
    end

    # Filter method to enforce a login requirement.
    #
    # To require logins for all actions, use this in your controllers:
    #
    #   before_filter :login_required
    #
    # To require logins for specific actions, use this in your controllers:
    #
    #   before_filter :login_required, :only => [ :edit, :update ]
    #
    # To skip this in a subclassed controller:
    #
    #   skip_before_filter :login_required
    #
    def login_required
#      username, passwd = get_auth_data
#      self.current_user ||= User.authenticate(username, passwd) || :false if username && passwd
      logged_in? && authorized? || access_denied
    end
    
    # Redirect as appropriate when an access request fails.
    #
    # The default action is to redirect to the login screen.
    #
    # Override this method in your controllers if you want to have special
    # behavior in case the user is not authorized
    # to access the requested action.  For example, a popup window might
    # simply close itself.
    def access_denied
      respond_to do |accepts|
        accepts.html do
          session[:return_to] = request.request_uri
          flash[:notice]      = 'Please login first'

          redirect_to :controller => :users, :action => :login, :id => 0
        end

        accepts.xml do
          headers["Status"]           = "Unauthorized"
          headers["WWW-Authenticate"] = %(Basic realm="Web Password")

          render :text => "Could't authenticate you", :status => '401 Unauthorized'
        end
      end

      false
    end
    
    # Redirect to the URI stored by the most recent store_location call or
    # to the passed default.
    def redirect_back_or_default(default = edit_user_path(User.find_by_username(params[:username])))
      session[:return_to] ? redirect_to_url(session[:return_to]) : redirect_to(default)
      session[:return_to] = nil
    end
    
    # Inclusion hook to make #current_user and #logged_in?
    # available as ActionView helper methods.
    def self.included(base)
      base.send :helper_method, :current_user, :logged_in?
    end

    # When called with before_filter :login_from_cookie will check for an :auth_token
    # cookie and log the user back in if apropriate
    def login_from_cookie
      return unless cookies[:auth_token] && !logged_in?
      user = User.find_by_remember_me_token cookies[:auth_token]
      self.current_user = user if user && user.remember_me_valid?
    end

#  private
#    @@http_auth_headers = %w(X-HTTP_AUTHORIZATION HTTP_AUTHORIZATION Authorization)
#    # gets BASIC auth info
#   def get_auth_data
#     auth_key  = @@http_auth_headers.detect { |h| request.env.has_key?(h) }
#     auth_data = request.env[auth_key].to_s.split unless auth_key.blank?
#     return auth_data && auth_data[0] == 'Basic' ? Base64.decode64(auth_data[1]).split(':')[0..1] : [nil, nil] 
#   end
end
